1. Field of Invention
The present invention relates to starting aid means for fluorescent lamps, more particularly to electronic fluorescent lamp starters.
2. Description of Prior Art
Fluorescent lamps of the type commonly referred to as Pre-Heat fluorescent lamps normally require some form of starting aid means in order to be properly initiated into operation. The type of starting aid means most commonly used for such Pre-Heat fluorescent lamps is the so-called glow-switch or glow-tube starter as used in conjunction with a simple reactor ballast.
While the glow-tube starter has the advantages of being widely used and low in cost, it has several significant disadvantages, such as: (i) inconsistent performance, in that it is often necessary for the starter to perform several starting cycles in order to get the lamp starter--with the result of annoying lamp blinking and starting delay; (ii) relatively short life expectancy, which implies that the glow-tube starter can not prudently be provided as a permanently built-in part of the ballast, nor as a permanently wired-in part of a lighting fixture; and (iii) non-conductive to long lamp life, which is partly due to the fact that the lamp starting voltage generated by the starter (with help of the reactor ballast), upon opening of its contacts, is (in order to have at least a reasonably good probability of providing adequate starting voltage even when contact-opening occurs at a non-optimum point in time) frequently excessively high, thereby producing excessive cathode wear and correspondingly shorter lamp life.
Aside from the glow-tube lamp starter, there are several other non-electronic lamp starters described in prior art literature, such as in General Electric's Bulletin L.D. 1 issued in January, 1956; and, there is also a number of electronic lamp starters described in prior art--such as for instance in the following U.S. Pat. Nos.: No. 3,701,925 to Nozawa et al; No. 3,818,268 to Peltz; No. 3,942,069 to Kaneda; and No. 4,119,887 to Iyama et al.
However, none of these various lamp starters appear to offer cost-effective solutions to the various disadvantages described above in connection with the regular glow-tube starter.